Failed Test: Tx Pa Detector - Nokia 6275 Rf Description And Troubleshooting

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3. Using an oscilloscope, check the I and Q input modulation wave forms at test
points. See
present with an AC swing of about 500mVpp, with an offset of +1.2V.
• If one or more waveforms is missing, look for SMD problems around these
resistors.
• If the SMD is good, replace the UEMEK.
4. Use an AAS-10 RF probe to probe the Cell Tx output of the Tx IC.
• If there is no RF or low RF, look for a faulty SMD around the Tx IC.
• If the SMD is okay, replace the N7000.
5. Probe the PA input.
• If the level is low, look for an SMD issue on the Tx filter.
• Reflow or replace the filter as necessary.
6. Probe the PA output.
• If the RF is missing or low, look for Vbatt voltages and SMD issues on and
around the PA.
• If these are okay, replace the PA.
7. Probe the duplexer output.
• If the RF is missing or low, reflow or replace the duplexer.
8. Probe the coupler output.
• If the RF is missing or low, reflow or replace the coupler.
9. Probe the diplexer output.
• If the RF is missing or low, reflow or replace the diplexer.

Failed Test: Tx PA Detector

Use the following steps if you encounter a failed test for the Tx PA detector:
10. Use Phoenix to set the mobile terminal into Local Mode and activate the Tx with
default output power.
11. The output power at the RF test connector should be 15dBm ± 4dB. If not, adjust
the PDM values or troubleshoot per procedure above.
12. Using a voltmeter on DC, probe the detector output at C7315. The voltmeter
should read approximately 1.7V. If not, replace N7302.
Issue 1 - September 2006
"Tx RF Components of the
Company Confidential
6275/6275i (RM-154)
RF Description and Troubleshooting
PWB" on page 19. They should all be
Page 17